Nowadays, in many conferences, it has become common to project images displayed on a personal computer and the like on a large screen by using a projector and the like, and attendees view the projected screen. In such conferences, attendees make explanations, ask questions, etc., while pointing at figures or characters on the screen.
There are some means of pointing at figures or characters on the projected screen. For example, a user uses a pointing stick or a laser pointer to directly point at the projected screen. As another means, a user uses an input device such as a mouse and a pointing device to move a cursor on the screen displaying figures and characters so as to point at the figures and characters (for example, see Patent Literature 3).
Further, as a pointing method in which a user does not use an input device, etc., there has been known a technology of detecting a fingertip of the user to display a cursor and allowing the user to point with the cursor (for example, see Patent Literature 1, Patent Literature 2 and Patent Literature 4).
Patent Literature 1, Patent Literature 2 and Patent Literature 4 disclose a technology of allowing a user to perform a pointing operation by detecting a fingertip position of the user based on a plurality of images acquired by an imaging unit such as a camera.